Fuel conditioning device



June 3, 1947.

G. M. BICKNELL FUEL CONDITIONING DEVICE Filed Aug. 19, 1944 INVENTOR; GEORGE. M. BICKNELL Patented June 3, 1947 rum. coNm'noNmo nnvron George M. Bicknell, St. Louis, Mo., aasignor to Carter Carburetor Corporation, St. Louis, Mo.,

a corporation of Delaware Application August 19, 1944, Serial No. 550,211 Claims. (01. 123-119) This invention relates to internal combustion engines and consists particularly in novel means to condition the fuel supplied thereto for improving the functioning thereof and for reducing detonation and, thereby, permitting the use of lower grade fuel without loss of power.

Internal combustion engines are known to detonate and to lose power when the compression in the engine cylinder is higher than a predetermined value, depending upon the grade of fuel used. Such high compression and detonation results when the engine is being accelerated or operated under a heavy load with the throttle substantially open. I have found thatthe admission of a small quantity of cooled exhaust gases to the engine intake, at such time, improves the functioning of the engine and reduces the detonation and, consequently, increases the power obtainable. This expedient also results in normal operation of the engine where a lower grade fuel is used than that for which the engine was originally designed.

It is desirable, however, that little or no exhaust be admitted during idling and during coldstarting and the warm-up period because the diluting effect of the exhaust at such time results in erratic engine operation. Furthermore, the exhaust gases during the starting and warm-up period frequently carry excessive quantities of unvaporized liquids and solid matter which have a deleterious effect upon the engine.

It is my belief that the advantageous results of the invention derive partly from the moisture carried in the exhaust gases and, consequently, I interpose a cooling device in the exhaust connection which, not only condenses some of the moisture but increases the thermal efilciency of the engine over that which would be obtained if uncooled exhaust gases were admitted. The exhaust cooler is particularly importantsince I admit exhaust gases from the engine at relatively high temperatures.

It is an object of the present invention to provide a device for application to an internal combustion engine for causing the admission of small quantities of exhaust gases and moisture thereto, at times when detonation is likely to occur and when the engine is operating at normal temperatures or above. 'Ihis object and other more detailed objects hereafter appearing are obtained by the device illustrated in the accompanying drawing in which Fig. 1 is a side view, partly cut away and sectioned, illustrating portions of an internal combustion engine and carburetor having the novel fuel conditioning device applied thereon.

Fig. 2 is a plan view of a detail of the exhaust cooling device.

The drawing illustrates a downdraft carburetor I attached in the usual manner to the intake manifold is of an internal combustion engine ,(not shown).

portion of the intake manifold. An exhaust pipe 9 leads the exhaust gases away from the engine. A by-pass exhaust pipe Ill extends upwardly from pipe Sand has apair of pivoted butterfly valves II and 12 therein. Pipe i0 terminates in a ribbed, cooling casing I3 which has. intermediately thereof, a partition it provided with a number of openings l5, formed, as shown, to cause swirling of gases descending throughthe cooler. A tube I 6 extends, from near the bottom of cooler 13 into a chamber l1 passage through which is controlled by a pivoted butterfly valve l8. Chamber i1 is connected by a pair of tubes l9 and to a, ring 2| disposed between the carburetor and the intake manifold through which exhaust gases are discharged into intake conduit 22.

Pivotal shaft 25, mounting butterfly valve i2, extends outwardly of theby-pass wall and receives the inner extremity of a coiled thermostat 26, which is. anchored at its outer end, as at 21. The thermostat is arranged to hold; valve i2 closed until the engine reaches normal operating temperature, at which time the valve is opened.

Butterfly valve Ii is controlled by an arm 29 rigid with valve shaft 30 and connected by link 3! to a second arm 32, rigid with carburetor throttle valve shaft 33. This operative connection is such that when the throttle valve is opened by its operating crank 34,exhaust valve H isalso opened. Preferably, link it has a lost motion connection 35 with arm 29, so thatwalve it will remain closed until the throttle has.

reached a substantially opened position, such as half open.

The third butterfly valve I8 is controlled by a crank 36 connected to the rod 31 of a piston 38 a working in a cylinder 39. Piston 38 is normally of the engine.

V this condition can exist only under engine operating conditions when detonation is likely to occur. No gases are admitted during idling or light load operation or during the starting and warmup period when dilution of the combustible mix- Mounted adjacent the intake manifold is an exhaust manifold 1 con nected to a hot spot 8 surrounding the central ture would be a disadvantage. Because of the cooler interposed in the exhaustconnectiomthe thermal efll'ciency of the engine is not greatly affected. I have found that all of the above controls, as well as an effective cooler, are necessary to obtain best operation. With the use of the device as described and hereafter claimed, detonation is noticeably reduced and, correlatively, the power of the engine under acceleration and heavy load conditions is increased. I have also found that carbon deposits about the firing chamber and valves are substantially reduced.

The invention may be modified in various respects as will occur to those skilled in the art and exclusive use of all modifications as come within the scope of the appended claims is contem plated.

I claim:

1. In combination with an internal combustion engine having an intake conduit, a throttle therein, and an exhaust pipe, an anti-detonation device comprising a connection leading from said exhaust pipe to said conduit posterior to said throttle, an .exhaust cooler and valve means in said connection, means operating said valve means from said throttle for closing said connection when said throttle is in idling position and in direct relation to the degree of closing of said throttle, and additional means for opening said valve means in inverse proportion to the suction existing in said intake conduit.

2. In an internal combustion engine having an exhaust pipe and an intake condiut with a throttle therein, an anti-detonation device comprising a connection between said exhaust pipe and said conduit posterior to said throttle, an exhaust cooler and a pair of valves in said connection, an operative connection between said throttle and one of said valves whereby said latter valve is closed when said throttle is in idling position and is opened when said throttle is substantially opened, and a device responsive to suction in said intake conduit posterior to said throttle for opening the other of said valves only when relatively low suction exists in said conduit.

3. In an internal combustion engine having an exhaust pipe and an intake conduit with a throttle therein, an anti-detonation device comprising aconnection between said exhaust pipe and said' 4 conduit posterior to said throttle, a pair of valves in said connection, an operative connection between one of said valves and said throttle whereby said valve is opened only when said throttle is substantially opened, and a thermostat controlling the other valve.

4. In an internal combustion engine having an exhaust pipe and an intake conduit with a throttle therein, an anti-detonation device comprising a connection between said exhaust pipe and said conduit posterior to said throttle, three valves in said connection, an operativeconnection between a first of said valves and said throttle whereby said first valve is opened only when said throttle is substantially open, a device responsive to suction posterior to said throttle for opening a second of said valves only when relativelylow suction exists in said conduit, and a thermostat for opening a third of said valves only when the engine is at, or above, normal operating temperature.

5. In an internal combustion engine having an thermostat, said controls and valve means being constructed and arranged to 0pm said connection to admit cooled exhaust to the engine only when said throttle substantially opened, when relatively low suction exists in said conduit, and when the engine temperature is at, or above,

. normal.

Number GEORGE M., BICKNE'LL.

REFERENCES CITED The followingreferences are of record in the file of this patent:

UNITED STATES PATENTS 

